Which of the following statements is incorrect?

• A
  Pure sodium metal dissolves in liquid ammonia to give a blue solution.
• B
  $NaOH$ reacts with glass to give sodium silicate.
• C
  Aluminium reacts with excess $NaOH$ to give $Al(OH)_3$.
• D
  $NaHCO_3$ on heating gives $Na_2CO_3$.